The use of carbon dioxide as a clean, abundant, and tunable solvent is potentially environmentally beneficial, and accordingly it is being investigated in a number of applications including, for example, cleaning protocols, coatings, and polymer production and processing. See e.g., Wells, S. L.; DeSimone, J. Angew. Chem. Int. Ed. 2001, 40, 518. Notwithstanding the above potential benefits, carbon dioxide is often limited in that many materials such as water exhibit limited solubility therein.
In response to these possible solubility limitations, fluorosurfactants have been developed to potentially assist in the dispersion of water in carbon dioxide. See e.g., Harrison, K.; Goveas, J.; Johnston, K. P.; O'Rear, E. A. Langmuir 1994, 10, 3536, Johnston, K. P.; Harrison, K. L.; Clarke, M. J.; Howdle, S. M.; Heitz, M. P.; Bright, F. V.; Carlier, C.; Randolph, T. W. Science 1996, 271, 624, Eastoe, J.; Bayazit, Z.; Martel, S.; Steytler, D. C.; Hennan, R. K. Langmuir 1996, 12, 1423, Eastoe, J.; Cazelles, B. M. H.; Steytler, D. C.; Holmes, J. H.; Pitt, A. R.; Wear, T. J.; Heenan, R. K. Langmuir 1997, 13, 6980, Zielinski, R. G.; Kline, S. R.; Kaler, E. W.; Rosov, N. Langmuir 1997, 13, 3934, Eastoe, J.; Downer, A.; Paul, A.; Steytler, D. C.; Rumsey, E.; Penfold, J.; Heenan, R. K. Phys. Chem. Chem. Phys. 2000, 2, 5235, Lee Jr., C. T.; Bhargava, P.; Johnston, K. P. J. Phys. Chem. B 2000, 104, 4448, Lee Jr., C. T.; Johnston, K. P.; Dai, H. J.; Cochran, H. D.; Melnichenko, Y. B.; Wignall, G. D. J. Phys. Chem. B 2001, 105, 3540, and Liu, Z.-T.; Erkey, C. Langmuir 2001, 17, 274. Accordingly, water-in-carbon dioxide (W/C) microemulsions containing appreciable water quantities have been achieved, allowing for their use in a number of applications such as nanoparticle synthesis, organic reactions, voltammetric measurements, and enzymatic conversions. See e.g., Holmes, J. D.; Bhargava, P. A.; Korgel, B. A.; Johnston, K. P. Langmuir 1999, 15, 6613, Ji, M.; Chen, X.; Wai, C. M.; Fulton, J. L. J. Am. Chem. Soc. 1999, 121, 2631, Jacobson, G. B.; Lee Jr., C. T.; Johnston, K. P. J. Org. Chem. 1999, 64, 1201, Ode, H.; Hunt, F.; Kithara, S.; Way, C. M. Anal. Chem. 2000, 72, 4738, Lee, D.; Hutchison, J. C.; Demimonde, J. M.; Murray, R. M. J. Am. Chem. Soc. 2001, 123, 8406, Holmes, J. D.; Settler, D. C.; Rees, G. D.; Robinson, B. H. Languor 1998, 14, 6371, and Kane, M. A.; Baker, G. A.; Pander, S.; Bright, F. V. Languor 2000, 16, 4901. W/C systems have also been the subject of computational treatments. See e.g., Satanically, S.; Cui, S. T.; Cummings, P. T.; Cochran, H. D. Languor 1999,15, 5188.
Nonetheless, inspite of any advantages of these systems, there remains a need in the art for surfactants and systems employing the same that allow for improved volatilization of various materials in carbon dioxide, such as, for example, water.